This invention relates to a tape cassette, and more particularly to a tape cassette which ensures smooth and positive traveling of a magnetic tape in a casing.
In a conventional tape cassette, as shown in FIGS. 7 and 8, lubricant sheet elements 100 formed by drawing are interposedly arranged between a casing 102 and tape windings 104 each constituted by a hub and the portion of a magnetic tape wound on the hub, to thereby allow the magnetic tape to smoothly and stably travel in the casing 102 without contacting with the inner surface of the casing. The sheet elements 100 each are formed with a projection 108 by pressing for improving the traveling and taking-up of the magnetic tape as well as various holes such as apertures 110 aligned with hub holes of the casing 102 for the purpose of positioning the sheet element 100 in place in the casing 102.
The projection 108 made by pressing is merely positioned at the central portion of the sheet element 100 sufficient to cover only the hub holes of the casing 102. Also, the sheet element 100 is formed into dimensions sufficient to cause both end edges of the sheet element extending in the longitudinal direction thereof to be contacted with the inner surface of the casing 102 and cause the sheet element 100 to substantially occupy a whole tape area defined in the casing. The words "tape area" used herein mean an area in the casing which is occupied by the tape windings 106 of a maximum diameter. Thus, the sheet element fails to exhibit a satisfactory cushioning function, as well as adequately keep the balance between the rigidity of the sheet element and its cushioning properties over a wide range.
Accordingly, it is highly desirable to provide a tape cassette which is capable of eliminating the foregoing disadvantages of the prior art to ensure smooth and positive traveling of a magnetic tape.